This invention relates to a high current power source used primarily to power a drive motor for automobiles such as hybrid and electric automobiles.
A high current power source used to power an automobile drive motor achieves high output voltage by series connection of many battery cells. This is for the purpose of increasing drive motor output. A power source used for this type of application contains a large number of battery cells to increase output electrical power. For example, this type of power source is cited in Japanese Non-examined Patent Publication No. 10-270006 issued Oct. 9, 1998. The power source disclosed in this patent application contains a plurality of power modules arranged in rows in a holder-case, and each power module has a plurality of batteries lined up in a column. The holder-case has circular through-holes in both end walls for insertion of long, slender columns of power modules. Further, intermediate walls are provided parallel to the end walls to retain power modules in a stable manner, and these intermediate walls also have circular through-holes. Power modules are inserted through the holes in both end walls and through the holes in the intermediate walls to retain the power modules in fixed positions within the holder-case.
After inserting power modules into the holder-case, both ends of the holder-case are closed off with end-plates. The end-plates have pass bars to connect respective electrode terminals established at the ends of each power module. Each power module is mechanically attached and electrically connected to pass bars by setscrew attachment at the end-plates.
In this power source, non-circular shaped nuts are provided at the positive electrode end and at the negative electrode end respectively of each power module. Power modules are attached to the pass bars of both end-plates by fastening threaded setscrews through holes provides in the pass bars to mate with the non-circular shaped nuts at power module electrodes.
The outline of a positive electrode nut and the outline of a negative electrode nut are shaped differently. The two types of electrode nuts are configured such that alignment of one on top of the other allows the shape of neither nut to completely include the other. Further, retaining grooves with shapes corresponding to the outlines of the electrode nuts are provided in the end-plates. Electrode nuts are inserted into, and held by these retaining grooves. Retaining grooves for insertion and holding of positive electrode nuts are shaped differently than retaining grooves for insertion and holding of negative electrode nuts.
This type of configuration allows simple attachment of power modules to pass bars via setscrew termination. Insertion and retention of non-circular shaped nuts into retaining grooves and attachment via setscrews prevents rotation of power modules during the attachment process. As a result, not only is the power module attachment process simplified, but development of twists between power module battery cells is prevented. Further, the problem of power module mis-insertion is solved by shaping positive electrode nuts and their corresponding retaining grooves.
However, as shown in FIG. 1, since the retaining grooves 124, which correspond to the outline shapes of the electrode nuts, are formed in the end-plates 103, the power source cited in the prior art disclosure has the drawback of end-plates 103 with complicated shapes. Further, each power module 101 must be inserted into retaining grooves 124 in the end-plates 103. Lining-up and inserting all of a large number, on the order of 20, power modules 101 is extremely difficult. In addition, since a large number of power modules 101 are retained in specified fixed positions, the system has the drawback of requiring very precise location of retaining grooves 124 in the end-plates 103.
Consequently, the present invention provides a power source which simplifies end-plate shape and end-plate processing, eases the operation of power module insertion into the holder-case while preventing power module rotation, and prevents backwards insertion of power module positive and negative ends.
The above and further objects and features of the invention will more fully be apparent from the following detailed description with accompanying drawings.